Dividing gun calibre by 6 gives you the shatter threshold, that's the minimum thickness of armour required to shatter HE shells on impact.
The data panel shows HE shell penetration, which is always less than the shatter threshold. In this case, those shells will penetrate 50mm of armour.

Manual AA or CE is probably going to be more useful than manual secondaries for a dedicated captain but it's a tier 6 premium, which IMO is low enough that you can play it as a captain trainer without needing 10+ points. My Bayern captain went into the ship with 8 points (6 assigned) and got AFT for his first 4-pointer; he'll get secondaries for the next one as he'll end up in the Bismarck in due course.

You mean a DD's AA may not be as strong as that of an AA cruiser? Hmm ... I suspect you might be right about that.
Black's AA should still be pretty good compared to other DDs though so I don't see whatever changes happen as being much of a stumbling block.

My initial impression is fairly positive too ...
I've had best results from the sea mines by dropping them at known chokepoints and forgetting about them (northern entry to D on Two Brothers was particularly successful). I haven't encountered anyone daft enough to straight-line for the length of time it takes the mines to arrive.
An unforeseen side-effect is that the mines are really helping my map knowledge as I have to think about where the enemy are likely to be, what areas I want to deny, etc., more so than with faster torps as I've always had the second thought of using them offensively.

I think you need a mod for that in Warships. The only option I can find is to display that truncated list of names or not display it at all, I play with it switched off and pull up the full list with TAB if I want to check a name.

I got absolutely owned by a Flint yesterday in my Duke of York, though that was more because he had support and could smoke up to spam me whereas my team chose the YOLO-oh-we've-sunk tactic which, to be fair, they excelled at. It's a bit too close to my Atlanta for me to be tempted into buying it though.
I spent my steel on the Black this morning and so far, I'm delighted. Managed a hit with the sea mines on an enemy Chung Mu and chased another DD out of his smoke with my radar. Great ship, certainly worth considering if you're a fan of gunboat DDs. I've been enjoying RN DDs recently, more than any other nation, and I've found it to be a good fit with a similar playstyle, though you'll want a 10-point captain at a minimum because at that tier everyone else will have at least that.

Because it was a direct nerf to the advertised statistics of the tank, not a change to the mechanics. They didn't offer refunds or change the two premium arties when they introduced stun, nor did they offer a refund of any money spent converting free xp for any tech tree SPGs so it's pretty clear that the SP instance was a one-off.

Have you considered that this change is being applied to all ships of that type (battle cruiser) in the game ... only there aren't more than four of them right now?
Possibly because that was before the power-creep occurred and is one of the reasons why the power-creep happened ...

To be fair, Stalingrad only has a win rate 9% better than the next best tier 10 cruiser and less than 35k more average damage while the Kronshtadt is in second place to the Alaska (figures from wows-numbers in spoiler)!
Remember when stealth firing was removed and the Blyskawica took a major dive in popularity? The fire mechanic is changing, the premium ship isn't. Besides, both ships can be bought for free using in-game resources (steel, free xp) so the "premium ship" argument isn't quite as compelling.

Decided to try my luck with the first daily container, received an SC with 100 Ouroboros signals.
I now have 179 Ouroboros signals, not that I'm bitter about receiving more. At least it's not Juliet Charlie to add to the 1,048 of those I have in the depot from previous SC and Santa crates (I use the magazine module on lower tier DDs).

To think, I'd avoided playing RN DDs because I thought they wouldn't suit how I like to play my DDs.
And they don't, it helps that recently I've changed my approach from blindly rushing in and hoping for the best to something a bit more patient and productive. 2k base xp, turned the battle around from the enemy having a pretty hefty lead to our winning on points with only their Dallas remaining, even picked up a couple of compliments along the way.
I thought I'd complete the Mighty Prinz mission for the Icarus and then park it in the garage until I finally got back to the grind but it's quickly become a favourite. Looking forward to seeing how this line develops, to the extent that I've stopped thinking about my Z-23 grind that's only about 20k short of researching the Z-46.

On the same team as @omglaserspewpew, he playing his Sims and I was in the Dallas doing the Prinz campaign 120 ribbons mission. Domination battle on Two Brothers, no one went middle for the memes but we had a rough start anyway as our Podvoisky didn't seem to know which way to turn. The enemy never really committed to the fight so we pretty much swept them up, towards the end I was beginning to worry that I wouldn't get all the ribbons in one battle but luckily their Texas decided that reversing broadside to a spamming Dallas sat behind an island was a good plan.